Steam baths conventionally comprise a steam generator, a steam dispensing head and a thermostat responsive to the temperature of the steam bath environment to maintain a desired temperature by selectively activating and deactivating the generation of steam. Early steam bath systems used thermostats comprising electrical contactors that turned the steam fully on or completely off, as needed. Such systems, however, typically resulted in significant temperature overshoots followed by a fall off in temperature to a point substantially below the desired temperature. In addition to energy inefficiencies caused by such hysteresis, systems of this type suffered from noise created by the system. Upon activation, steam would rush out of the steam dispensing head with an audible sound until the steam would be shut off by the opening of the contactors. This, in turn, would typically cause a further disturbing sound. As steam baths moved out of commercial environments and into private homes, the noises and energy waste became increasingly undesirable.
Newer steam bath systems accordingly began to employ electronic controls which reduced hysteresis and resulted in quieter operation. Rather than being fully on or completely off, steam could be generated at an adjustable rate between those two extremes to heat the steam environment and then maintain it at the desired temperature with a relatively low rate of steam generation that generally offset the cooling of the environment.
The use of electronic controls, however, created a need for reliably cooling its electronic components to avoid temperature-related system failures. By way of example, a typical 15 kilowatt heater employed to generate 15 lbs of steam per hour can draw approximately 70 amps of current through the electronic switching used to control the environment's temperature. Consequently, the switching devices (e.g., triacs) have been mounted on relatively large heat sinks, and fans have been used to enhance thermal transfer away from the switching devices as well. The use of heat sinks and fans have not only added to the cost and size of the systems, but have frequently become a source of problems in themselves. In addition to the potential for normal fan failures, the fans and switching devices of steam baths are typically mounted out of sight in dirty and/or dusty environments such as attics, basements and the like, where they are virtually never inspected or cleaned until there is a failure. Heat sinks become less efficient as dirt accumulates on them, and fans become less reliable in such environments as well. One need only look at the fan on the back of one's personal computer to appreciate how dirt and dust accumulate even in the relatively clean working and living quarters of an office or home.